Friday, 13 January 2017

Red Admiral

The Red Admiral hibernates in small numbers in Britain, with the majority of these butterflies arriving on our shores from mainland Europe, starting off from North Africa and, Southern Europe.

Our hibernating Red Admirals emerge from their slumber, normally in early March, and are the first to start breeding. Laying their eggs [ova, ovum] normally on the top of small/fresh leaves and, sometimes on the flowers of the Common Nettle, [Commas are also known to lay their eggs on Nettle flowers] in full sun. The earliest i have witnessed a female ovipositing was on 16th March. The eggs hatch after about one week. There is one brood a year, extended over several months with the first butterflies making an appearance as early as the middle of May, continuing right through to November.

Red Admiral ovum unusually on the underside of a Nettle leaf
photo taken 19th March

Red Admiral ovum on Nettle flower
photo taken 20th July

The tiny larva on emerging are quite colourful and, it's body is covered in small sparse hairs somewhat similar to that of a newly emerged 1st instar Comma larva.The tiny caterpillar will then build a hide-away in the form of a tent made from Nettle leaves.

Before they have their first moult, they have already developed a spiky appearance, which will stay with them throughout their life as a caterpillar.The larval stage lasts about 24-30 days, and they have 4 moults [5 instars].

1st instar Red admiral larva, having just emerged

1st instar Red Admiral larva 24 hours before it's first moult

2nd instar Red Admiral Larva

3rd instar Red Admiral larva

4th instar Red Admiral larva making another tent

5th instar Red Admiral larva

A Red Admiral larval tent

When the Red Admiral final instar is ready to pupate, it will seek out a suitable clump of Nettle leaves with which to make a final tent. This last tent will be more like an umbrella shape rather than a tent which it had lived in as a larva. This is done so that the butterfly, when it emerges from the pupa has more freedom of movement and, doesn't damage it's wings when expanding them, and can fly away unhindered. If the tent had been shaped like a larval tent, how would the butterfly emerge from an enclosed structure?.......

Red Admiral 5th instar larva just starting to pupate under it's opened umbrella
shaped tent, leaving the butterfly plenty of room when it emerges
3rd June 16.57 pm